METHOD FOR MANUFACTURING A DENTAL PART FROM A DENTAL FORM BLOCK

Description

Technical area

[0001] The present invention relates to a method for producing a dental prosthesis part from a dental prosthesis mold block. State of the art

[0002] One-piece dental implants, in which the abutment part is firmly connected to the implant, are currently prefabricated in standard shapes. These standard implants can be made of ceramic or titanium, for example, and can be linear or angled. However, customizing one-piece standard implants is difficult because the prefabricated parts must be held and processed extraorally, taking into account the subsequent screw-in rotation and screw-in height. Customizing standard implants only after they have been inserted and healed into the jaw is very difficult, as the applied energy could heat or loosen the parts.

[0003] An alternative to standard implants is therefore implants that consist of several parts. Here, an implant screw is a separate standard part that can be screwed into a customizable abutment. This can then be easily processed extraorally. However, with a multi-part implant, gaps can form between the individual elements. These gaps can allow bacteria to migrate into the interior of the implant and, over time, to migrate out from there intermittently due to the mechanical effects of chewing and infect the bone. This leads to peri-implantitis, which manifests itself in bone resorption and subsequent implant loss. In addition, mechanical wear can occur at the connection between the elements in multi-part implants. After several million chewing cycles, the screw loosens and with it the abutment, or the screw may even break.

[0004] Automated CAD / CAM processes are increasingly being used to manufacture the abutments for multi-component implants, in which the respective dental prosthesis component is machined from a dental prosthesis block. This enables manufacturers to offer consistently high quality and precise fit of the dental prosthesis at affordable prices.

[0005] US2012251979A1 discloses blanks for dental implants and methods for their production. WO2008009272A1 discloses implants.

[0006] It is an object of the present invention to provide a dental prosthesis mold block from which a dental prosthesis can be manufactured using a CAD / CAM process that does not have the aforementioned disadvantages of multi-part implants. A further object of the invention is to provide a method for producing such a dental prosthesis. Description of the invention

[0007] This object is achieved by the method according to claim 1. The subject matter of the dependent claims relates to further advantageous embodiments.

[0008] According to the invention, a dental prosthesis mold block for producing a dental prosthesis, in particular an implant, is provided, which block has an inner material that is at least partially surrounded by an outer material. The hardness of the inner material differs from the hardness of the outer material. Hardness is understood in particular to be the Vikers hardness according to the standard DIN EN ISO 6507-1:2005 to -4:2005. In this way, the inner material can be used as the starting material for producing a post with a self-tapping external thread, and the outer material can serve as the starting material for a superstructure.

[0009] The inner material forms part of a first surface of the denture block. The post is machined from the first surface by removing material.

[0010] It is therefore possible to fabricate a one-piece dental prosthesis in the form of an implant extraorally using a CAD / CAM process. This combines the advantage of the one-piece design of standard implants—that individual components cannot loosen and that no gaps can form in the implant that could be colonized by bacteria—with the advantage of multi-piece implants—that the superstructure can be fabricated extraorally. This fabrication does not have to take place in a dental laboratory, but can also be performed in a dental practice.

[0011] The inner material is preferably completely surrounded by the outer material at the first surface. All other surfaces of the denture block preferably consist of the outer material. Thus, after material removal, the pin protrudes from the first surface and is otherwise completely surrounded by the outer material.

[0012] In a preferred embodiment, the inner material has a lower hardness than the outer material. The inner material is particularly preferably a metal, such as titanium (Vikers hardness approx. 200 HV 10). The outer material in this embodiment is particularly preferably a ceramic, such as zirconium dioxide (ZrO 2 , Vikers hardness approx. 1250 HV 10) or lithium disilicate (Vikers hardness approx. 650 HV 10) or glass ceramic. This enables, on the one hand, secure anchoring of the dental prosthesis in the jaw by means of the metal pin formed from the inner material and, on the other hand, an aesthetically pleasing design of the ceramic structure. The structure is given particular stability by the fact that the metal, as the inner material, is at least partially surrounded by an outer material even in the finished implant. In addition, the pin is formed integrally with the inner material, which remains in the ceramic.In one embodiment, the inner material has a greater hardness than the outer material. Particularly preferably, the inner material is a metal and the outer material is a ceramic.

[0013] In another particularly preferred embodiment, the inner material and the outer material are metals. In this case, the metal of the outer material is harder than the metal of the inner material. Titanium (Vikers hardness approx. 200 HV 10) is advantageous as the inner material due to its good biocompatibility and healing properties, while a cobalt-chromium alloy (CoCr, Vikers hardness approx. 300 HV 10) is advantageous as the outer material due to its cost-effectiveness.

[0014] In yet another embodiment, the inner material has a greater hardness than the outer material. Zirconium dioxide (ZrO2, Vikers hardness approx. 1250 HV 10) is advantageous as the inner material due to its biocompatibility and aesthetics. A cobalt-chromium alloy (CoCr, Vikers hardness approx. 300 HV 10) is advantageous as the outer material due to its cost-effectiveness, or a lithium disilicate (Vikers hardness approx. 650 HV 10) or glass ceramic is advantageous due to its aesthetics and processability.

[0015] In a preferred form of the denture block, it has an internal thread extending from a second surface into the inner material. The second surface is opposite the first surface. This allows additional elements to be screwed onto the one-piece implant after it has been manufactured.

[0016] In the method according to the invention, a dental prosthesis mold block is first prepared. The dental prosthesis part is manufactured by removing material from the dental prosthesis mold block. This is carried out using a CAD / CAM process. A pin with a self-tapping external thread is formed from a portion of the inner material.

[0017] The process therefore makes it possible to use known CAD / CAM techniques to produce a one-piece dental prosthesis, in particular an implant, from the dental prosthesis block.

[0018] In principle, the denture block can be made of a single material, such as zirconium dioxide. In this case, the direction of material removal is chosen so that the post is formed from a portion of the inner material.

[0019] Unlike the processing of one-piece standard implants, which must be clamped using their pin, the dental prosthesis block can be fixed via one of its surfaces using a CAD / CAM process. The pin is then preferably first formed in a first area of the dental prosthesis block by completely removing the outer material and partially removing the inner material. Then, in a second area of the dental prosthesis block, the outer material is partially removed so that the inner material in the second area is not exposed on any surface of the dental prosthesis block. The dental prosthesis part is preferably manufactured based on patient data so that it can be individually adapted to the patient's needs.

[0020] If the dental prosthesis block has an internal thread extending from the second surface into the inner material, the dental prosthesis part is preferably manufactured such that a dental prosthesis element can be screwed into the internal thread of the dental prosthesis part. The dental prosthesis element can be, for example, an abutment. In this embodiment, the one-piece dental prosthesis part then merely forms a base for the abutment.

[0021] Furthermore, a computer program is disclosed which is not part of the claimed invention and which is designed to carry out all steps of the method according to the invention when run on a computer. It enables the implementation of different embodiments of the method on a computer of a dental CAD / CAM system without having to make structural changes. For this purpose, it is stored, in particular, on a machine-readable data carrier.

[0022] By loading the computer program onto a conventional dental CAD / CAM system, a dental CAD / CAM system is obtained that is configured to perform the procedure.

[0023] Brief description of the drawings Embodiments of the inventions are illustrated in drawings and are explained in more detail in the following description. Fig. 1 shows an isometric view of a dental prosthesis mold block according to an embodiment of the invention. Fig. 2 shows a cross-sectional view of the denture block according to Fig. 1 . Fig. 3 shows an isometric view of a dental prosthesis mold block according to another embodiment of the invention. Fig. 4 shows a cross-sectional view of the denture block according to Fig. 3 . Fig. 5 shows a first processing step of a dental prosthesis mold block in a method according to an embodiment of the invention. Fig. 6 shows a second processing step of a dental prosthesis mold block in a method according to an embodiment of the invention. Fig. 7 shows a third processing step of a dental prosthesis mold block in a method according to an embodiment of the invention. Fig. 8 shows a cross-sectional view of a dental prosthesis part which can be produced by means of an embodiment of the method according to the invention. Examples of implementation

[0024] A dental prosthesis mold block 10 according to a first embodiment of the invention is shown in the Fig. 1 und 2 It is cuboid-shaped and has a surface 11 and a second surface 12 opposite it. A core of the dental prosthesis mold block 10 consists of titanium as an inner material 13. Zirconium dioxide is pressed onto this as an outer material 14. As a result, the first surface 11 consists partly of titanium and partly of zirconium dioxide, while all other surfaces of the dental prosthesis mold block 10 consist exclusively of zirconium dioxide. The inner material 13 is exposed at surface 11 and is surrounded there in a frame-like manner by the outer material 14. All other surfaces of the dental prosthesis mold block 10 are formed by the outer material.

[0025] In a second and third embodiment of the dental prosthesis mold block 10, the core of the dental prosthesis mold block 10 consists of titanium as an inner material 13. The outer material 14 is a cobalt-chromium alloy (second embodiment) or a glass ceramic (third embodiment).

[0026] In a fourth, fifth and sixth embodiment of the dental prosthesis mold block 10, the core of the dental prosthesis mold block 10 consists of zirconium dioxide as an inner material 13. The outer material 14 is titanium (fourth embodiment), a cobalt-chromium alloy (fifth embodiment) or a glass ceramic (sixth embodiment).

[0027] In a seventh embodiment of the dental prosthesis mold block 10, which is shown in the Fig. 3 und 4 As shown, it consists of the same materials as in one of the previous embodiments. Starting from the second surface 12, an opening 15 extends through the outer material 14 into the inner material 13. While the region 151 in the outer material 14 has smooth inner walls, the region 152 in the inner material 13 is provided with an internal thread.

[0028] In a first embodiment of the method according to the invention, a desired shape of a dental prosthesis part is determined in a dental CAD / CAM system 30 based on patient data. This data can be obtained, for example, using an intraoral camera. A dental prosthesis mold block 10 according to one of the previously described embodiments is then inserted into the CAD / CAM system 30 and fixed there at its second surface 12 by means of a block holder 31. This is shown in Fig. 5 shown. Material removal tools 32, 33 are positioned above and below the dental prosthesis mold block 10.

[0029] By means of the material removal tools 32, 33, material is removed from the dental prosthesis block 10, starting at the first surface 11, in order to initially form a pin 20 with a self-cutting external thread. This is shown in Fig. 6 For this purpose, in a first area of the denture mold block 10, the outer material 14

[0030] The inner material 13 is partially removed in this area to form the pin 20. As shown in Fig. 7 As shown, a dental prosthesis part 50 is subsequently formed, which, at the end of the material removal, is only connected to the dental prosthesis mold block 10 via a cutout 51. For this purpose, the outer material 14 is partially removed in a second region of the dental prosthesis mold block 10 without exposing the inner material 13 in this second region. After removing the cutout 51, the finished dental prosthesis part 50, which is formed integrally with the pin 20, can be removed from the CAD / CAM system 30.

[0031] If the dental prosthesis part 50 was manufactured from a dental prosthesis mold block 10 according to its seventh embodiment, it still has the internal thread between the pin 20 and a surface created during the material removal process, which surface is opposite the pin 20. The area 151 of the opening 15, which has no internal thread, was completely removed. A dental prosthesis supply element 60 in the form of an abutment can be screwed into the internal thread by means of a screw 61, as shown in Fig. 8 is shown.

[0032] In a second embodiment of the method according to the invention, a desired shape of a dental prosthesis is also determined in the dental CAD / CAM system 30 based on patient data. A dental prosthesis mold block 10, which consists entirely of zirconium dioxide, is then inserted into the CAD / CAM system 30 and fixed there at its second surface 12 by means of the block holder 31. This is shown in Fig. 9 shown. By means of the material removal tools 32, 33, starting at the first surface 11, material is removed from the dental prosthesis block 10 in order to initially form a pin 20 with a self-tapping external thread. This is shown in Fig. 10 Then, as in Fig. 7A dental prosthesis part 50 is shown, which, at the end of the material removal, is only connected to the dental prosthesis mold block 10 via a cutout 51. For this purpose, the zirconium dioxide is removed. After removing the cutout 51, the finished dental prosthesis part 50, which is formed integrally with the pin 20 and consists exclusively of zirconium dioxide, can be removed from the CAD / CAM system 30.

[0033] The examples of the dental prosthesis mold block and the method described above enable the one-piece, individualized production of dental prosthesis parts in the form of implants.

Claims

1. Method for producing a dental prosthetic item (50), comprising: - providing a dental prosthetic block (10), wherein the dental prosthetic block (10) has an inner material (13) which is at least partially surrounded by an outer material (14) whose hardness differs from the hardness of the inner material (13), wherein the inner material (13) forms part of a first surface (11) of the dental prosthetic block (10), and - producing the dental prosthetic item (50) by removing material from the dental prosthetic block (10) by means of a CAD / CAM process, characterized in that a pin (20) with a self-tapping external thread is formed, wherein the pin (20) is formed from a part of the inner material (13).

2. Method according to Claim 1, characterized in that firstly in a first region of the dental prosthetic block (10) the pin (20) is formed by completely removing the outer material (14) and partially removing the inner material (13) and then in a second region of the dental prosthetic block (10) the outer material (14) is partially removed such that the inner material (13) is not exposed on any surface of the dental prosthetic block (10) in the second region.

3. Method according to one of Claims 1 to 2, characterized in that the dental prosthetic block has an internal thread (15) which extends from a second surface (12) opposite the first surface (11) into the inner material.

4. Method according to Claim 3, characterized in that the dental prosthetic item (50) is produced in such a way that a dental prosthetic supply element (60) can be screwed into the internal thread (15) of the dental prosthetic item (50).

5. Method according to one of Claims 1 to 4, characterized in that the dental prosthetic item (50) is produced in accordance with data of a patient.

6. Method according to one of Claims 1, 2 or 5, characterized in that the inner material (13) is completely surrounded by the outer material (14) on the first surface (11), and that all other surfaces of the dental prosthetic block consist of the outer material (14).

7. Method according to one of Claims 1 to 6, characterized in that the inner material (13) has a lower hardness than the outer material (14).

8. Method according to Claim 7, characterized in that the inner material (13) is a metal and the outer material (14) is a ceramic.

9. Method according to Claim 7, characterized in that the inner material (13) and the outer material (14) are metals.

10. Method according to one of Claims 1 to 5, characterized in that the inner material (13) has a greater hardness than the outer material (14).

11. Method according to Claim 10, characterized in that the inner material (13) is a ceramic.